Air-brake release



. March 6, 1928.

' J. s. McwHlRTER AIR BRAKE RELEASE Filed Aug. 4. 1926 u Fi @wfwmw@ fik/7 Patented Mar. 6, 1928.

recrue JoHN s. MCWHIRTEE, oENEw YORK. N. Y.

` AIE-BRAKE EELEAsE.

Application filed August 4, 1926. Serial No. 126,911.9.

This invention relates `to a novel apparatus for releasing the brakes on vehicles.

More particularly this invention relates to a novel means for causing the 'release of the brakes on railroad cars, street cars and the like.

One of the objects of this invention is the provision of a novel pneumatic arrangement for releasing the brakes on vehicles after the brake applying mechanism has been deenergized. 1 y

A still further object of this invention is the provision of a device of this type lwhich is inter-connected with the fluid pressure source vused for applying the brakes so that when the brake applying mechanism is deenergized the brake releasing mechanism is automaticallyv energized. i

A further object of this invention is a provision of a novel fluid pressure operated valve for automatically carrying out this operation. c

These and many other objects are obtained by means of the construction described herein. i

This invention resides substantially in the construction, combination, arrangement kand relativelocation of parts as will be more fully described hereinafter.

Referring to the drawings for which the same reference numerals will be used to indicate the same or similar parts,

Figure 1 is a diagrammatic viewl of the apparatus employed in myinvention;

Fig. 2 is a cross-sectional view of the novel valve comprising one element of this invention; and y Fig. 3 shows a modified device for releasing the brakes.

At the presenttime it is almost a univer'- sal practice in releasing air brakes to equip i the brake rigging at'some point with releasing springs either coiled or flat with or without suitable adjustment for regulating the amount of pressure to be applied to the brake shoes. It is also common to install Within the brake cylinder,'a suitable coil spring to aid the movement of the return strokeof the piston to release the` brakes.

It has been found in practice that it is almost impossible to adjust the various release springs in suchy a. manner as to apply equal pressure to all the shoes. In the event that unequal pressure is applied, the tendency is for one spring to overcomethe tension of another', thus pulling the shoe on the strong spring away from the wheel and forcing the shoe on the spring toward the wheel resulting in shoe drag. When thel brakes are Vapplied, a considerable portion of the energ is used in compressing these springs whicli lowers the braking eljhciency since an excessof the braking power with what is actually ieeded to brake the train must be provided Inmy invention the springs in the brake cylinder, as well as the other springs applied to the brake shoes are dispensed with and the brakes are released by means of a small air cylinder mounted in such a manner either through levers or by direct connection, to oppose the main brake cylinder and automatically operated vthrough a valve when `the brake cylinder is deenergized.

Referring to the drawings the fluid pres` sure source is shown at 1, connected through a pipe 3 to an auxiliary fluid pressure source 2. This sourceis connected through a pipe 4 to my novel valve S which will be described shortly. A small cylinder 5 is connected to this valve by `means of the pipe 9, the piston rod 6 is attached to the brake rigging comprising the lever 7 pivotedat 10 andV pivotally connected to the piston rod 11 of the brake cylinder 12 in which is mounted for sliding movement the piston 13. This brake cylinder is of the usual construction.` Another rod lever 14 is pivoted to they end of the piston rod 11 and is connected by means of the pivoted rod 15 to the pivoted lever 16 as shown. The rods 17 and 1S are connected to thelevers 1G and 14 respectively. y

Another pipe 19 extends from the source l to the usual valve 2l through the pipe 20. A return pipe 22 connects the valve with the brake cylinder through the pipe 23. The pipeQQ also extends to the valve 8 through the pipe 24 and continues on to' a similar valve 21 to'which the pipe 2O also extends.

ln F ig. 2 is shown the valve construction which comprises casing 8 in which ,thepiston 'moves when fluid pressure is supplied thereto against the action ofthespring 41. A circumferential groove 4t2 extends around the piston 40 and when the piston is in its normaler deenergized position, this groove connects the two pipes 4. and 9 together. I y

The operation of this device is somewhat i) Il pivotally ieu y lli.)

as follows: When the brakes are applied through operating the valves 21 or 21 which are of the usual construction and are adaptto the pipe 20 ed to connect the pipes 22 so that fluid pressure is-supplied to the cylinder 12. This moves piston 13 to the right and causes the brakes which are attached to the rods 17 and 18 to be applied. At the same time fluid pressure is supplied to the valve 8 to force the pistone() to the rightto move the groove'lfout of register with the pipes 4 and-9 and to permit cylinder 5 to exhaust through pipes J and 25. lVhen the valve 21 or 21 is moved to its other position the pipe Z2 is open to exhaust so that the cylinder 19. may exhaust therethrough. At the y`same time piston 40 m the valve 8 moves back to its normal position under the inlluence of spring 41 since it is open to exhaust also. This places the pipes 4 and 9 in communication and-lluid pressure Hows 4from the auxiliary source 2 to the cylinder 5 in which the piston thereof moves to the lett to force the lever 7 to the lett about its pivot 10, 'I`his causes the piston 13 to move over towards the left to its deenergized position. It will be seen therefore that I have supplied a piston meansfor releasing the brakes which is interconnected with the system for operating the brake cylinder so that the means become automatically active when the brake cylinder is open to exhaust.

I have shown a modification of this arrangement in Fig. 8 Where two cylinders 50 are Vprovided which are connected to the pipes 19 from the valve 8. IVithin these cylinders move the pistons 51 whose rods extend through the walls of: cylinder 1Q and against the piston 13 as shown in dotted lines at52. The operation oit' this apparatus is the same except that the torce ofthe pistons 51 is directly applied to the piston 13 as will he readily apparent in the drawings.

Iam Well aware that 'many changes in the details of construction an relative arrangement of` the parts will readily suggest themselves to those skilled in the art and I do not therefore desire to be limited to the particular construction disclosed herein but rather to the principles of my invention as it is defined in the appended claims.

YVhat I seek to secure by United States Letters Patent is:

1. In a brake release mechanism the combination with pneumatic air brake applying means including a piston of means interconnected with said brake applying means for releasing the brakes when the brake applying means is deenergized, said interconnected means being mechanically fastened to the piston of said pneumatic means.

2. In an air brake release mechanism the combination with a brake applying cylinder and a piston of a releasing cylinder and vpiston energized when said brake applying c 'ylinder is deenergized.

3. In an air brake system the combination with a fluid pressure reservoir, a brake a plying means and means for controlling t e admission 'of Huid pressure to said means o means for releasing the brakes when said means is exhausted, vsaid `brake releasing means comprising a' cylinder and piston. h

4. In an air brake systein'the combination with a fluid pressure reservoir, a brake applying means, and means for controlling the admission of liuid pressure to saidmeans of pneumatic means for releasing thebrakes when said means is released, said means in-k cluding a valve adapted to energize said releasing means when said brake applying means is deenergized.

In an air brake system thecombination with a fluid pressure reservoir, a brake a plying means, and means for controlling tie admission ot' liuid 4pressure to Said means of means mcchanicall connected to the brake mechanism for re easing thefbrakes when said means is opened toeXhaust., i

6. In a brake release system the combination with a fluid pressure reservoir, means for applying the brakes and means forcom trolling the application of the brakes of means mechanicallyconnected to said brake applying means -lor releasing, the brakcsand a valve for energizing said releasing means when the brake applying means is deenergizec 7. In a brake release system the combination with a fluid pressure reservoir, means for applying the brakes andl means for controlling the application of' the brake 4oi means for releasing the brakes and a spring pressedvalve for energizing said releasing means when the brake applying means is deenergized.

8. In an air brake system the combination with a Huid pressure source and brake applying means of means mechanically counected to said brakeapplying means for releasing the brake and means for energizing the releasing means when the brake applying means is deenergized. f

In testimony whereof l have hereunto set my hand on this 29th day of July A. D., 1926.

JOHN S..McWr-1IR'I`ER. 

